When the link is explicitly disabled through the control interface reset
the error statistics counter.
There is usually little benefit to preserving until after the link has been
disabled. If software is interested in the values it can read them before
disabling the link. Having them reset makes the behavior consistent with
all other internal state of the jesd204 RX peripheral, which is reset when
the link is disabled.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>